Evaluating the Safety of Retrograde Intrarenal Surgery (RIRS): Intra- and Early Postoperative Complications in Patients Enrolled in the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR).

PURPOSE: To assess the incidence of the most common intra- and early postoperative complications following RIRS in a large series of patients with kidney stones. METHODS: We conducted a retrospective analysis of patients with kidney stones who underwent RIRS across 21 centers from January 2018 to August 2021, as part of the Global Multicenter Flexible Ureteroscopy Outcome (FLEXOR) Registry. RESULTS: Among 6669 patients undergoing RIRS, 4.5% experienced intraoperative pelvicalyceal system bleeding without necessitating blood transfusion. Only 0.1% of patients, required a blood transfusion. The second most frequent intraoperative complication was ureteric injury due to the ureteral access sheath requiring stenting (1.8% of patients). Postoperatively, the most prevalent early complications were fever/infections requiring antibiotics (6.3%), blood transfusions (5.5%), and sepsis necessitating intensive care unit admission (1.3%). In cases of ureteric injury, a notably higher percentage of patients exhibited multiple stones and stone(s) in the lower pole, and these cases were correlated with prolonged lasing and overall surgical time. Hematuria requiring a blood transfusion was associated with an increased prevalence of larger median maximum stone diameters, particularly among patients with stones exceeding 20 mm. Furthermore, these cases exhibited a significant prolongation in surgical time. Sepsis necessitating admission to the intensive care unit was more prevalent among the elderly, concomitant with a significantly larger median maximum stone diameter. CONCLUSIONS: Our analysis showed that RIRS has a good safety profile but bleeding requiring transfusions, ureteric injury, fever, and sepsis are still the most common complications despite advancements in technology.

Urologists' opinion on treating asymptomatic stones: Would we treat ourselves as we treat our patients? Survey from European Association of Urology, Young Academic Urologists, Endourology and Urolithiasis working party.

Background/aim: Management of asymptomatic kidney stones is an ongoing debate with follow-up and treatment guidelines based on low-level evidence. Our aim was to evaluate current management of asymptomatic urinary stones. Materials and methods: A 70-question survey was designed in collaboration with European Association of Urology, Young Academic Urologists, Section of Uro-Technology and Section of Urolithiasis groups and distributed. Responders filled out hypothetical scenarios from 2 perspectives, either as treating physicians, or as patients themselves. Results: A total of 212 (40.01%) responses were obtained. Median responder age was 39 years. 75% of responders were interested in "urolithiasis". 82.5% had never experienced a renal colic, 89.6% had never undergone urolithiasis treatment.Overall, as the kidney stone scenarios got more complicated, the invasiveness of the treatment preference increased. As "the physician", responders preferred the conservative option in all situations more than they would choose as "the patient". For ureteral stones, conservative approach was most preferred for small stones and ureteroscopy became more preferred as the stone size increased.For smaller kidney stones, the most preferred follow-up schedule was 4-6 monthly, whereas for larger and complicated stones it was 0-3 monthly from both perspectives respectively. For all ureteral stone scenarios, 0-4 weekly follow-up was mostly preferred.Interestingly, having had a renal colic was an independent predictor of an interventional approach, whereas having had an intervention was an independent predictor of a conservative approach. Conclusion: Current treatment and follow-up patterns of asymptomatic urinary stones are in agreement with international guidelines on symptomatic stones.In most of the urolithiasis situations urologists chose a conservative approach for their patients compared to what they would prefer for themselves. Conversely, urologists, in the scenarios as "the patient", would like to have a more frequent follow-up schedule for their stones compared to how they would follow-up their patients.

Radiation exposure of urologists during endourological procedures: a systematic review.

INTRODUCTION: Ionizing radiation is used daily during endourological procedures. Despite the dangers of both deterministic and stochastic effects of radiation, there is a lack of knowledge and awareness among urologists. This study reviewed the literature to identify the radiation exposure (RE) of urologists during endourological procedures. METHODS: A literature search of the Medline, Web of Science, and Google Scholar databases was conducted to collect articles related to the radiation dose to urologists during endourological procedures. A total of 1966 articles were screened. 21 publications met the inclusion criteria using the PRIMA standards. RESULTS: Twenty-one studies were included, of which 14 were prospective. There was a large variation in the mean RE to the urologist between studies. PCNL had the highest RE to the urologist, especially in the prone position. RE to the eyes and hands was highest in prone PCNL, compared to supine PCNL. Wearing a thyroid shield and lead apron resulted in a reduction of RE ranging between 94.1 and 100%. Educational courses about the possible dangers of radiation decreased RE and increased awareness among endourologists. CONCLUSIONS: This is the first systematic review in the literature analyzing RE to urologists over a time period of more than four decades. Wearing protective garments such as lead glasses, a thyroid shield, and a lead apron are essential to protect the urologist from radiation. Educational courses on radiation should be encouraged to further reduce RE and increase awareness on the harmful effects of radiation, as the awareness of endourologists is currently very low.

Retrograde intrarenal surgery for asymptomatic incidental renal stones: a retrospective, real-world data analysis.

OBJECTIVE: To determine surgical outcomes and stone-free rates (SFRs) when offering upfront retrograde intrarenal surgery (RIRS) to patients with asymptomatic incidental renal stones (AIRS), as active surveillance, shockwave lithotripsy or upfront intervention in patients with AIRS is still a debate among urologists. PATIENTS AND METHODS: This retrospective FLEXible Ureteroscopy Outcomes Registry (FLEXOR), supported by the Team of Worldwide Endourological Researchers (TOWER), examines adult patients who underwent RIRS. We analysed a subset of asymptomatic patients with renal stones on imaging who were treated with RIRS. Data includes patient characteristics, stone specifications, anaesthesia type, perioperative details, complications, and SFR. A multivariable logistic regression analysis was performed to assess factors associated with the SFR. RESULTS: Among 679 patients with AIRS, 640 met the inclusion criteria. The median age was 55 years, with 33.4% being female. In all, 22.1% had positive urine cultures. The median stone diameter was 12 mm, commonly in lower and interpolar locations. RIRS was preferentially performed under general anaesthesia using a reusable scope in 443 cases. Prophylactic antibiotics were administered to 314 patients. The median operation time was 58 min and the median laser time was 24 min. The SFR was 68.8%. The use of holmium laser (odds ratio [OR] 0.21, 95% confidence interval [CI] 0.06-0.63; P < 0.01) and multiple stones (OR 0.38, 95% CI 0.19-0.76; P < 0.01) were factors associated with lower odds of being stone free. Overall complications were minimal, with sepsis in 1.6% of patients. Re-interventions were performed in 76 cases (11.8%), with RIRS being the most common in 67 cases (10.6%). CONCLUSION: Our multicentre real-world study is the first of its kind that highlights the pros and cons of offering RIRS to patients with AIRS and demonstrates a favourable SFR with acceptable complications. Pre-emptively discussing potential re-intervention helps patients make informed decisions, particularly in cases involving large and multiple stones.

Experts' recommendations in laser use for the treatment of urolithiasis: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training-Research in Urological Surgery and Technology (T.R.U.S.T.)-Group.

PURPOSE: To identify laser lithotripsy settings used by experts for specific clinical scenarios and to identify preventive measures to reduce complications. METHODS: After literature research to identify relevant questions, a survey was conducted and sent to laser experts. Participants were asked for preferred laser settings during specific clinical lithotripsy scenarios. Different settings were compared for the reported laser types, and common settings and preventive measures were identified. RESULTS: Twenty-six laser experts fully returned the survey. Holmium-yttrium-aluminum-garnet (Ho:YAG) was the primary laser used (88%), followed by thulium fiber laser (TFL) (42%) and pulsed thulium-yttrium-aluminum-garnet (Tm:YAG) (23%). For most scenarios, we could not identify relevant differences among laser settings. However, the laser power was significantly different for middle-ureteral (p = 0.027), pelvic (p = 0.047), and lower pole stone (p = 0.018) lithotripsy. Fragmentation or a combined fragmentation with dusting was more common for Ho:YAG and pulsed Tm:YAG lasers, whereas dusting or a combination of dusting and fragmentation was more common for TFL lasers. Experts prefer long pulse modes for Ho:YAG lasers to short pulse modes for TFL lasers. Thermal injury due to temperature development during lithotripsy is seriously considered by experts, with preventive measures applied routinely. CONCLUSIONS: Laser settings do not vary significantly between commonly used lasers for lithotripsy. Lithotripsy techniques and settings mainly depend on the generated laser pulse's and generator settings' physical characteristics. Preventive measures such as maximum power limits, intermittent laser activation, and ureteral access sheaths are commonly used by experts to decrease thermal injury-caused complications.

Worldwide trends of practice and intervention in paediatric endourology: comparison of European versus Non-European responses.

Introduction: The area of paediatric endourology is unique and is recognised to be challenging, and it requires a certain level of focused training and expertise. Our aim was to conduct a worldwide survey in order to gain an overview regarding the current practice patterns for minimally invasive treatments of paediatric upper urinary tract stone patients. Material and methods: The survey was distributed between December 2021 and April 2022 through urology sections and societies in United Kingdom, Latin America and Asia. The survey was made up of 20 questions and it was distributed online using the free online Google Forms (TM). Results: 221 urologists answered the survey with 56 responses each from India, South America and UK and 53 responses from the rest of Europe (15 countries). In total, 163 responders (73.7%) managed paediatric stone patients in their daily practice. Of the responders, 60.2% were adult urologists and 39.8% were paediatric urologists. 12.9% adult urologists and 20.4% paediatric urologists run independent clinics while some run combined adult and paediatric clinics sometimes with the support of the nephrologists. Only 33.9% urologists offered all surgical treatments [extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), ureteroscopy (URS) and retrograde intrarenal surgery (RIRS)]. Conclusions: Treatment of paediatric stones can vary according to country and legislations. Based on the results of this survey, minimally invasive methods such as URS and mini PCNL seem to have become more popular. In most institutions a collaboration exists between adult and paediatric urologists, which is the key for a tailored decision making, counselling and treatment success.

Experts' recommendations in laser use for the treatment of upper tract urothelial carcinoma: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training Research in Urological Surgery and Technology (T.R.U.S.T.) group.

PURPOSE: To highlight and compare experts' laser settings during endoscopic laser treatment of upper tract urothelial carcinoma (UTUC), to identify measures to reduce complications, and to propose guidance for endourologists. METHODS: Following a focused literature search to identify relevant questions, a survey was sent to laser experts. We asked participants for typical settings during specific scenarios (ureteroscopy (URS), retrograde intrarenal surgery (RIRS), and percutaneous treatment). These settings were compared among the reported laser types to find common settings and limits. Additionally, we identified preventive measures commonly applied during surgery. RESULTS: Twenty experts completed the survey, needing a mean time of 12.7 min. Overall, most common laser type was Holmium-Yttrium-Aluminum-Garnet (Ho:YAG) (70%, 14/20) followed by Thulium fiber laser (TFL) (45%, 9/20), pulsed Thulium-Yttrium-Aluminum-Garnet (Tm:YAG) (3/20, 15%), and continuous wave (cw)Tm:YAG (1/20, 5%). Pulse energy for the treatment of distal ureteral tumors was significantly different with median settings of 0.9 J, 1 J and 0.45 J for Ho:YAG, TFL and pulsed Tm:YAG, respectively (p = 0.048). During URS and RIRS, pulse shapes were significantly different, with Ho:YAG being used in long pulse and TFL in short pulse mode (all p < 0.05). We did not find further disparities. CONCLUSION: Ho:YAG is used by most experts, while TFL is the most promising alternative. Laser settings largely do not vary significantly. However, further research with novel lasers is necessary to define the optimal approach. With the recent introduction of small caliber and more flexible scopes, minimal-invasive UTUC treatment is further undergoing an extension of applicability in appropriately selected patients.

Outcomes of Flexible Ureteroscopy vs Extracorporeal Shock Wave Lithotripsy for Renal Stones in Pediatric Patients: A European Association of Urology Urolithiasis Guidelines Systematic Review and Meta-Analysis.

PURPOSE: We sought to determine which treatment between flexible ureteroscopy and shock wave lithotripsy has a better stone-free rate in pediatric patients (<18 years) with renal or proximal ureteric stones (<2 cm). Subanalysis for all outcomes for randomized controlled trials only. MATERIALS AND METHODS: Using PubMed, Web of Science, and the Cochrane database, we identified studies (randomized clinical trials and prospective comparative nonrandomized studies) published until August 2022 reporting surgical outcomes of pediatrics patients undergoing flexible ureteroscopy and shock wave lithotripsy with renal or proximal ureteric stones <2 cm (PROSPERO ID: CRD42022378790). Only randomized controlled trials were considered for meta-analysis. Stone-free rate, operative time, and complications were analyzed. Analysis was performed in R. RESULTS: A total of 6 studies identified, of which 3 were randomized clinical trials and 4 had data on renal stones. A total of 669 patients were analyzed. Mean age ranged from 4.4 to 12.4 years. The shock wave lithotripsy group presented a range of stone-free rate between 21 and 90% while the flexible ureteroscopy group presented a range of stone-free rates between 37% and 97%. Meta-analysis of randomized controlled trials only (n=302) demonstrated significantly higher stone-free rate in flexible ureteroscopy vs shock wave lithotripsy (RR = 1.17, 95% CI: 1.04-1.33, P = 0.01), operative time (mean difference = +16.4 minutes, 95% CI: 7.3-25.5, P < 0.01) and hospital stay (mean difference = +0.25 days, 95% CI: 0.14-0.36, P < 0.001). But no difference in fluoroscopy exposure time (mean difference = -21.0 seconds, 95% CI: -42.6 to 0.56, P = 0.07), Clavien I-II (RR = 1.23, 95% CI: 0.71-2.12, P = 0.45) or Clavien III-V complications (RR = 1.04, 95% CI: 0.32-3.42, P = 0.95). CONCLUSIONS: Flexible ureteroscopy has a significantly higher stone-free rate than shock wave lithotripsy, with no difference in complication rate or fluoroscopy exposure time, and significantly higher operative times and hospital stay. However, the current evidence base for this is weak and further randomized trials are needed.

What to expect from the novel pulsed thulium:YAG laser? A systematic review of endourological applications.

INTRODUCTION: Several preclinical studies about a novel pulsed-thulium:yttrium-aluminum-garnet (p-Tm:YAG) device have been published, demonstrating its possible clinical relevance. METHODS: We systematically reviewed the reality and expectations for this new p-Tm:YAG technology. A PubMed, Scopus and Embase search were performed. All relevant studies and data identified in the bibliographic search were selected, categorized, and summarized. RESULTS: Tm:YAG is a solid state diode-pumped laser that emits at a wavelength of 2013 nm, in the infrared spectrum. Despite being close to the Ho:YAG emission wavelength (2120 nm), Tm:YAG is much closer to the water absorption peak and has higher absorption coefficient in liquid water. At present, there very few evaluations of the commercially available p-Tm:YAG devices. There is a lack of information on how the technical aspects, functionality and pulse mechanism can be maximized for clinical utility. Available preclinical studies suggest that p-Tm:YAG laser may potentially increase the ablated stone weight as compared to Ho:YAG under specific condition and similar laser parameters, showing lower retropulsion as well. Regarding laser safety, a preclinical study observed similar absolute temperature and cumulative equivalent minutes at 43° C as compared to Ho:YAG. Finally, laser-associated soft-tissue damage was assessed at histological level, showing similar extent of alterations due to coagulation and necrosis when compared with the other clinically relevant lasers. CONCLUSIONS: The p-Tm:YAG appears to be a potential alternative to the Ho:YAG and TFL according to these preliminary laboratory data. Due to its novelty, further studies are needed to broaden our understanding of its functioning and clinical applicability.

New Technologies in Endourology and Laser Lithotripsy: The Need for Evidence in Comprehensive Clinical Settings.

Flexible ureteroscopy (fURS) with laser lithotripsy is currently the gold standard surgical treatment for ureteral and kidney stones with a maximum diameter of 2 cm [...].

Does unenhanced computerized tomography as imaging standard post-retrograde intrarenal surgery paradoxically reduce stone-free rate and increase additional treatment for residual fragments? Outcomes from 5395 patients in the FLEXOR study by the TOWER group.

Background: Assessment of residual fragments (RFs) is a key step after treatment of kidney stones. Objective: To evaluate differences in RFs estimation based on unenhanced computerized tomography (CT) versus X-rays/ultrasound after retrograde intrarenal surgery (RIRS) for kidney stones. Design: A retrospective analysis of data from 20 centers of adult patients who had RIRS was done (January 2018-August 2021). Methods: Exclusion criteria: ureteric stones, anomalous kidneys, bilateral renal stones. Patients were divided into two groups (group 1: CT; group 2: plain X-rays or combination of X-rays/ultrasound within 3 months after RIRS). Clinically significant RFs (CSRFs) were considered RFs ⩾ 4 mm. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Multivariable logistic regression analysis was performed to evaluate independent predictors of CSRFs. Results: A total of 5395 patients were included (1748 in group 1; 3647 in group 2). After matching, 608 patients from each group with comparable baseline and stone characteristics were included. CSRFs were diagnosed in 1132 patients in the overall cohort (21.0%). Post-operative CT reported a significantly higher number of patients with RFs ⩾ 4 mm, before (35.7% versus 13.9%, p < 0.001) and after matching (43.1% versus 23.9%, p < 0.001). Only 21.8% of patients in the matched cohort had an ancillary procedure post-RIRS which was significantly higher in group 1 (74.8% versus 47.6%, p < 0.001). Age [OR 1.015 95% confidence interval (CI) 1.009-1.020, p < 0.001], stone size (OR 1.028 95% CI 1.017-1.040, p < 0.001), multiple stones (OR 1.171 95% CI 1.025-1.339, p = 0.021), lower pole stone (OR 1.853 95% CI 1.557-2.204, p < 0.001) and the use of post-operative CT scan (OR 5.9883 95% CI 5.094-7.037, p < 0.001) had significantly higher odds of having CSRFs. Conclusions: CT is the only reliable imaging to assess the burden of RFs following RIRS and urologist should consider at least one CT scan to determine the same and definitely plan reintervention only based on CT rather than ultrasound and X-ray combination.

Instrumental dead space and proximal working channel connector design in flexible ureteroscopy: a new concept.

Objective: The objective of this study was to evaluate a new concept in flexible ureteroscopy: instrumental dead space (IDS). For this purpose, various proximal working channel connector designs, as well as the impact of ancillary devices occupying the working channel were evaluated in currently available flexible ureteroscopes. Design and methods: IDS was defined as the volume of saline irrigation needed to inject at the proximal connector for delivery at the distal working channel tip. Because IDS is related to working channel diameter and length, proximal connector design, as well as occupation of working channel by ancillary devices, these parameters were also reviewed. Results: IDS significantly varied between flexible ureteroscope models, ranging from 1.1 ml for the Pusen bare scopes, to 2.3 ml for Olympus scopes with their 4-way connector (p < 0.001). Proximal connector designs showed a high degree of variability in the number of available Luer locks, valves, seals, angles, and rotative characteristics. The measured length of the working channel of bare scopes ranged between 739 and 854 mm and significantly correlated with measured IDS (R2 = 0.82, p < 0.001). The coupling of scopes with an alternative ancillary proximal connector and the insertion of ancillary devices into the working channel significantly reduced IDS (mean IDS reduction of 0.1 to 0.5 ml; p < 0.001). Conclusions: IDS appears as a new parameter that should be considered for future applications of flexible ureteroscopes. A low IDS seems desirable for several clinical applications. The main factors impacting IDS are working channel and proximal connector design, as well as ancillary devices inserted into the working channel. Future studies should clarify how reducing IDS may affect irrigation flow, intrarenal pressure, and direct in-scope suction, as well as evaluate the most desirable proximal connector design properties.

Comparison of Treatment Outcomes for Fluoroscopic and Fluoroscopy-free Endourological Procedures: A Systematic Review on Behalf of the European Association of Urology Urolithiasis Guidelines Panel.

CONTEXT: Endourological procedures frequently require fluoroscopic guidance, which results in harmful radiation exposure to patients and staff. One clinician-controlled method for decreasing exposure to ionising radiation in patients with urolithiasis is to avoid the use of intraoperative fluoroscopy during stone intervention procedures. OBJECTIVE: To comparatively assess the benefits and risks of "fluoroscopy-free" and fluoroscopic endourological interventions in patients with urolithiasis. EVIDENCE ACQUISITION: A systematic review of the literature from 1970 to 2022 was performed using the MEDLINE/PubMed, Embase, and Cochrane controlled trials databases and ClinicalTrials.gov. Primary outcomes assessed were complications and the stone-free rate (SFR). Studies reporting data on ureteroscopy and percutaneous nephrolithotomy (PCNL) were eligible for inclusion. Secondary outcomes were operative duration, hospital length of stay, conversion from a fluoroscopy-free to a fluoroscopic procedure, and requirement for an auxiliary procedure to achieve stone clearance. EVIDENCE SYNTHESIS: In total, 24 studies (12 randomised and 12 observational) out of 834 abstracts screened were eligible for analysis. There were 4564 patients with urolithiasis in total, of whom 2309 underwent a fluoroscopy-free procedure and 2255 underwent a comparative fluoroscopic procedure for treatment of urolithiasis. Pooled analysis of all procedures revealed no significant difference between the groups in SFR (p = 0.84), operative duration (p = 0.11), or length of stay (p = 0.13). Complication rates were significantly higher in the fluoroscopy group (p = 0.009). The incidence of conversion from a fluoroscopy-free to a fluoroscopic procedure was 2.84%. Similar results were noted in subanalyses for ureteroscopy (n = 2647) and PCNL (n = 1917). When only randomised studies were analysed (n = 12), the overall complication rate was significantly in the fluoroscopy group (p < 0.001). CONCLUSIONS: For carefully selected patients with urolithiasis, fluoroscopy-free and fluoroscopic endourological procedures have comparable stone-free and complication rates when performed by experienced urologists. In addition, the conversion rate from a fluoroscopy-free to a fluoroscopic endourological procedure is low at 2.84%. These findings are important for clinicians and patients, as the detrimental health effects of ionising radiation are negated with fluoroscopy-free procedures. PATIENT SUMMARY: We compared treatments for kidney stones with and without the use of radiation. We found that kidney stone procedures without the use of radiation can be safely performed by experienced urologists in patients with normal kidney anatomy. These findings are important, as they indicate that the harmful effects of radiation can be avoided during kidney stone surgery.

Estimated Radiation Dose to the Lens During Endourologic Procedures: The Role of Leaded Glasses and the ALARA Protocol-An ESU/ESUT-YAU Endourology Group Collaboration.

Purpose: On February 6, 2018, the European Atomic Energy Community reduced the annual equivalent dose limit for the lens from 150 to 20 mSv/year, because of its association with cataracts at low radiation doses. Our aim was to estimate the radiation doses received by the lens during endourologic procedures that require fluoroscopy. Materials and Methods: Multicenter study including prospective data of annual eye dosimeters between 2017 and 2020. Four endourologists used an eye dosimeter in endourologic procedures that require fluoroscopy (ureteroscopy, retrograde intrarenal surgery, and percutaneous nephrolithotomy). Surgeons 1 and 2 wore leaded glasses; surgeon 1 also used the as low as reasonably achievable (ALARA) protocol. Descriptive statistical analysis using SPSS 25.0 was conducted. Results: Surgeons 1, 2, 3, and 4 performed a median of 159, 586, 102, and 129 endourologic procedures per year, respectively, for a total of 641, 2340, 413, and 350 procedures between 2017 and 2020. The median annual dose of lens radiation exposure was 0.16, 1.18, 3.79, and 1.42 mSv per year, respectively, which corresponds to 0.001, 0.009, 0.024, and 0.012 mSv per procedure. The two surgeons who used leaded glasses registered a lower radiation dose per procedure (0.001 vs 0.027). Similarly, the urologist who used the ALARA protocol registered the lowest lens radiation dose compared with the three surgeons who did not use it (0.001 vs 0.023). Conclusions: The endourologists who participated in this study effectively comply with current guidelines on radiation exposure to the lens. Registered eye lens radiation does not seem to be related to the number of procedures but rather to the use of leaded glasses and the ALARA protocol.

Influence of pre-stenting on RIRS outcomes. Inferences from patients of the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR).

BACKGROUND: Retrograde Intrarenal Surgery (RIRS) is recommended as an alternative to percutaneous nephrolithotomy for stones up to 2 cm. Pre-stenting before RIRS remains controversial with various studies differing in outcomes and recommendations. We aim to understand how pre-stenting influences surgical outcomes. METHODS: A number of 6579 patients from the TOWER group registry were divided into pre-stented (group 1) and non-pre-stented groups (group 2). Patients aged ≥18 years old, with normal calyceal anatomy were enrolled. Patients with ureteric stones, anomalous kidneys, bilateral stones, planned for ECIRS were excluded. RESULTS: Patients are homogeneously distributed in both groups (3112 vs. 3467). The predominant indication for pre-stenting was symptom relief. Overall stone size was comparable, whilst group 1 had a significantly more multiple (1419 vs. 1283, P<0.001) and lower-pole (LP) stones (1503 vs. 1411, P<0.001). The mean operative time for group 2 was significantly longer (68.17 vs. 58.92, P<0.001). Stone size, LP stones, age, recurrence and multiple stones are contributing factors for residual fragments at the multivariable analysis. The incidence of postoperative day 1 fever and sepsis was significantly higher in group 2, indicating that pre-stenting is associated with a lower risk of post-RIRS infection and a lower overall complications rate (13.62% vs. 15.89%) (P<0.001). CONCLUSIONS: RIRS without pre-stenting can be considered safe without significant morbidity. Multiple, lower-pole and large stone is a significant contributor towards residual fragments. Patients who were not pre-stented had significantly higher but low-grade complications, especially for lower pole and large volume stones. While we do not advocate routine pre-stenting, a tailored approach for these patients should include proper counselling regarding pre-stenting.

Comparison Between Holmium:YAG Laser with MOSES Technology vs Thulium Fiber Laser Lithotripsy in Retrograde Intrarenal Surgery for Kidney Stones in Adults: A Propensity Score-matched Analysis From the FLEXible Ureteroscopy Outcomes Registry.

PURPOSE: We evaluated stone-free rate and complications after flexible ureteroscopy for renal stones, comparing thulium fiber laser and holmium:YAG laser with MOSES technology. MATERIALS AND METHODS: Data from adults who underwent flexible ureteroscopy in 20 centers worldwide were retrospectively reviewed (January 2018-August 2021). Patients with ureteral stones, concomitant bilateral procedures, and combined procedures were excluded. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Stone-free rate was defined as absence of fragments >2 mm on imaging within 3 months after surgery. Multivariable logistic regression analysis was performed to evaluate independent predictors of being stone-free. RESULTS: Of 2,075 included patients, holmium:YAG laser with MOSES technology was used in 508 patients and thulium fiber laser in 1,567 patients. After matching, 284 patients from each group with comparable baseline characteristics were included. Pure dusting was applied in 6.0% of cases in holmium:YAG laser with MOSES technology compared with 26% in thulium fiber laser. There was a higher rate of basket extraction in holmium:YAG laser with MOSES technology (89% vs 43%, P < .001). Total operation time and lasing time were similar. Nine patients had sepsis in thulium fiber laser vs none in holmium:YAG laser with MOSES technology (P = .007). Higher stone-free rate was achieved in thulium fiber laser (85% vs 56%, P < .001). At multivariable analysis, the use of thulium fiber laser and ureteral access sheath ≥8F had significantly higher odds of being stone-free. Lasing time, multiple stones, stone diameter, and use of disposable scopes showed significantly lower odds of being stone-free. CONCLUSIONS: This real-world study favors the use of thulium fiber laser over holmium:YAG laser with MOSES technology in flexible ureteroscopy for renal stones by way of its higher single-stage stone-free rate.

Ultrasound-Guided PCNL - Why Are We Still Performing Exclusively Fluoroscopic Access?

PURPOSE OF REVIEW: While urologists are traditionally taught to perform percutaneous nephrolithotomy (PCNL) utilizing exclusively fluoroscopy, ultrasound has emerged as a safe alternative. This article showcases the major reasons why ultrasound-guided access should be considered the first-line approach for performing access for PCNL. RECENT FINDINGS: There continues to be a need to further reduce radiation exposure in the management of kidney stone patients. This review showcases how performing ultrasound-guided PCNL has been associated with a shorter learning curve, increased patient safety, and the ability to perform x-ray free PCNL. Ultrasound-guided PCNL is not only an achievable skill for urologists to learn but provides multiple advantages over traditional fluoroscopic access. As every effort should be given to help reduce radiation exposure for kidney stone patients as well as performing surgeons and operating theater personnel, endourologists should strive to add this technique to their armamentarium.

Comprehensive overview of ureteral stents based on clinical aspects, material and design.

Ureteral stents are useful devices in urological surgery. The main objective of a ureteric stent is to allow passage of urine and reduce early or late complications related to obstruction in the urinary tract. Despite their widespread use, there is a general lack of knowledge and awareness in stent composition and indication of application. We represented a synthesis of our extensive research over materials, coatings and shapes available on the market and then analyzed the main characteristics and peculiarities of ureteral stents. We have also focused our attention over the side effects and complication that must be considered when placing a ureteral stent. Encrustation, microbial colonization, stent-related symptoms and patient's history must always be evaluated when there is the need for a ureteral stent. The perfect stent should have many characteristics including easy insertion and removal, easy manipulation, resistance to encrustation and migration, lack of complications, biocompatibility, radio-opacity, biodurability, affordability (cost-effectiveness), tolerability and optimal flow characteristics. Nevertheless, further research and studies need to be done to provide more information about stent composition and efficacy in vivo. In this narrative review, we covered the basic information and main characteristics of ureteral stents, in order to help clinicians choose the appropriate device needed for a given situation.